2nd/10_Wiki/Dev/Topic_PHP/PHP_XML_Parser_Expat.md

id, title, category, status, verification_status, canonical_id, aliases, duplicate_of, source_trust_level, confidence_score, created_at, updated_at, review_reason, merge_history, tags, raw_sources, applied_in, github_commit

id	title	category	status	verification_status	canonical_id	aliases	duplicate_of	source_trust_level	confidence_score	created_at	updated_at	review_reason	merge_history	tags	raw_sources	applied_in	github_commit
php-xml-parser-expat	PHP XML Parser Expat	Programming_Language	draft	conceptual		Expat parser event-based XML PHP XML Expat 파서		B	0.88	2026-07-04	2026-07-04			php programming w3schools xml expat	https://www.w3schools.com/php/php_xml_parser_expat.asp

PHP XML Parser Expat

🎯 한 줄 통찰 (One-line insight)

The Expat parser reduces even a simple tag like <from>Jani</from> into exactly THREE distinct events — start element, character data, end element — and each event type is routed to its own separate handler function, meaning parsing an XML document is really about writing three small callback functions rather than writing traversal logic. [S1]

🧠 핵심 개념 (Core concepts)

• XML Expat Parser — event-based, non-validating (ignores DTDs), fast, low-memory; part of PHP core. [S1]
• Three-event model — any tag decomposes into: start element, CDATA/character data, end element. [S1]
• xml_parser_create() — initializes the parser. [S1]
• xml_set_element_handler($parser, "start", "stop") — registers separate functions for opening and closing tags. [S1]
• xml_set_character_data_handler($parser, "char") — registers the function for text content between tags. [S1]
• xml_parse($parser, $data, $isFinal) — feeds a chunk of data to the parser; feof($stream) signals whether this is the final chunk. [S1]
• xml_error_string() / xml_parser_free() — error reporting and resource cleanup. [S1]

📖 세부 내용 (Details)

• Handler functions: function start($parser, $element_name, $element_attrs) { switch($element_name) { case "NOTE": echo "-- Note --<br>"; break; case "TO": echo "To: "; break; ... } } function stop($parser, $element_name) { echo "<br>"; } function char($parser, $data) { echo $data; }. [S1]
• Full parse pipeline: $stream = fopen("note.xml", "r"); $parser = xml_parser_create(); xml_set_element_handler($parser, "start", "stop"); xml_set_character_data_handler($parser, "char"); while ($data = fread($stream, 4096)) { xml_parse($parser, $data, feof($stream)) or die(...); } xml_parser_free($parser); fclose($stream);. [S1]

⚖️ 모순 및 업데이트 (Contradictions & updates)

소스에서 모순되는 정보는 발견되지 않음.

🛠️ 적용 사례 (Applied in summary)

현재 발견된 실제 적용 사례가 없습니다 — note.xml을 이벤트 핸들러로 파싱해 "To: Tove" 형태로 출력하는 것이 이벤트 기반 파싱의 대표 실전 사례다. [S1]

💻 코드 패턴 (Code patterns)

Full Expat parsing pipeline with handler functions (PHP):

$stream = fopen("note.xml", "r");
$parser = xml_parser_create();
xml_set_element_handler($parser, "start", "stop");
xml_set_character_data_handler($parser, "char");
while ($data = fread($stream, 4096)) {
    xml_parse($parser, $data, feof($stream)) or die("XML Error");
}
xml_parser_free($parser);
fclose($stream);

✅ 검증 상태 및 신뢰도

• 상태: draft
• 검증 단계: conceptual
• 출처 신뢰도: B (W3Schools — widely used educational reference, not a primary standards body)
• 신뢰 점수: 0.88
• 중복 검사 결과: 신규 생성 (New discovery)

🔗 지식 그래프 (Knowledge Graph)

• 상위/루트: PHP Tutorial
• 관련 개념: PHP XML SimpleXML Get, PHP XML DOM
• 참조 맥락: 이벤트 기반 파싱 — 트리 기반 DOM 파서 챕터와 대비됨.

📚 출처 (Sources)

• [S1] W3Schools — PHP XML Expat Parser — https://www.w3schools.com/php/php_xml_parser_expat.asp

📝 변경 이력 (Change history)

• 2026-07-04: Initial draft synthesized from the W3Schools "PHP XML Expat Parser" page (Astra wiki-curation, P-Reinforce v3.1 format).